Cisco Certified Network Associate (CCNA) Practice Exam

Which tunneling is specifically meant to be used inside a site, not between two dual stacked edge services?

1. 6to4 tunneling

2. ISATAP tunneling

3. GRE tunneling

4. Teredo tunneling

The correct answer is: ISATAP tunneling

ISATAP tunneling is designed specifically for use within a single organization, facilitating IPv6 communications over an existing IPv4 network environment. The name "Intra-Site Automatic Tunnel Addressing Protocol" emphasizes its primary purpose, which is to enable communication within the same site or administrative domain where both IPv4 and IPv6 can coexist. This tunneling mechanism allows IPv6-capable hosts to communicate with one another over an IPv4 infrastructure by treating the IPv4 network as a transparent substrate. This capability is particularly useful in transitional scenarios where organizations may be gradually migrating from IPv4 to IPv6 but require their internal services to function seamlessly in a dual-stack environment. Other tunneling methods, such as 6to4, GRE, and Teredo, serve different purposes or contexts. For instance, 6to4 operates between different networks, enabling communication between isolated IPv6 networks over the Internet, which does not align with the requirement of internal site usage. GRE is a versatile protocol that can encapsulate numerous protocol types and is often utilized for point-to-point connections across the broader Internet. Teredo is primarily focused on allowing IPv6 connectivity in scenarios where only IPv4 connectivity is available, often used in peer-to-peer networks and through NAT devices,